A Birch Hill man has become the first person to have a murder conviction quashed following a change in the law.

Jon Clinton’s legal team argued he ‘lost control’ before killing wife Dawn at their home in Inchwood after she taunted him about her other sexual partners.

On Tuesday, Lord Chief Justice Lord Judge sitting at the Court of Appeal, overturned Clinton’s conviction, stating “sexual infidelity” by victims must be taken into account by jurors when considering if the defence is triggered.

The changes in the law abolished the common law defence to murder of provocation and replaced it with a new defence of “loss of control”.

Lord Judge’s ruling will be referred to by judges in future trials when directing juries on the defence, introduced by the Coroners and Justice Act 2009.

Tesco worker Mrs Clinton, 33, was hit with a length of wood and strangled with rope at the family home on November 15, 2010.

During his trial at Reading Crown Court in May, Clinton, 45, admitted killing his wife but denied murder.

It was the prosecution case that her killing was a planned act of revenge after he discovered her affair.

Clinton said his wife, a former dinner lady at Birch Hill Primary School, “evinced pure hatred” of him before he killed her, going into “graphic details” about what she had done with different men she said she had recently had sex with.

Clinton insisted he lost control after his wife told him of her sexual infidelity, saying he felt “useless, awful, confused and fearful” and his wife’s “horrible” outburst made her seem like a different person.

He said he felt the walls and ceiling closing in and just “wanted everything to stop” when he grabbed a piece of wood and began the attack.

Lord Judge, sitting with two other senior judges, ruled the trial judge “misdirected herself about the possible relevance of the wife’s infidelity” and was wrong to withdraw the “loss of control” defence from the jury.

He said Mrs Clinton’s infidelity and other potentially provocative factors meant reasonable jurors could have concluded the “loss of control” defence applied and the issue should have been left to them to decide.

Although Parliament laid down that sexual infidelity by itself will not be enough to trigger the new defence, Lord Judge said the “simple reality” was that it could not be “compartmentalised” and excluded when it was one of the factors potentially causing a loss of control.

He told the court: “To seek to compartmentalise sexual infidelity and exclude it when it is integral to the facts as a whole is not only much more difficult, but is unrealistic and carries with it the potential for injustice.”

Two other men convicted of murdering their wives, Steven Parker, 25, of Scunthorpe, Lincs, and Dewi Evans, 62, of Pontyberem, Camarthenshire, had their appeals dismissed by Lord Judge, who said jurors had been entitled to reject the “loss of control” defence in their cases.

Clinton will be held in custody awaiting a retrial on the murder charge on a date to be set.